CalDreamin
Member
It's a lot more difficult to "brick" the Model S high voltage battery than the OP indicates. It's not necessary to check the car every day when on vacation.I am not keen about replying to Tesla's anonymous post. If I don't reply, I assumed to be wrong. If I do reply, I will be attacked by many of Tesla's fans who will never let the facts get in the way. I do know that my issues with my Tesla and how Tesla is treating me are not unique. There are other owners who own lemons. I am the only owner who has hired an attorney.
- The car charging cable (UMC) failed while I was on vacation (winter 2014). Had I not diligently checked on my car, the battery would have been “bricked” (ruined beyond repair). The car has a well-known loss of power; it “leaks” electricity (vampire loss). Tesla requires all owners of the Model S to plug in their cars all the time. If the defective charging cable had not been discovered, my car would have been ruined. A neighbor was nice enough to change the cable that Tesla delivered while I was on vacation. If the neighbor had not replaced the cable, I would have had to fly home. So all Tesla owners, be advised, if you go on vacation, you may come back to a ruined car if you don’t check the charge status of your Model S every day. Tesla does not check. If I hadn’t been compulsive and checked the car every day with my remote iPhone app, the car’s $30,000 battery would have been ruined. The Tesla engineers still don’t know why the charge cable failed.
At the start of Winter 2014 -- the time frame referenced by the OP -- all Model S had received an OTA notice to upgrade to Firmware 5.8. Some Model S were already on earlier versions of 5.x by that time.
Firmware 5.x reduced the vampire drain to 3 rated miles per day (1% per day). I confirmed this by leaving my S85 unplugged and unused during Winter 2014 for a 34-day long vampire drain test with Firmware 5.8, which I documented here. Bjorn Nyland documented a similar vampire drain (slightly less than I observed) when he went on a Winter 2014 vacation and left his Model S85 unplugged for 27 days; he posted about that here.
If you go on vacation and leave your Model S unplugged with a standard (90%) charge, on Firmware 5.x you'd need to be gone for almost 3 months for the vampire drain to discharge the usable portion of an S85 HV battery. With Firmware 4.x or earlier, the higher rate of vampire loss might have reached this SOC in about 1 month.
If the usable portion of the Model S battery is completely discharged, the Model S will disconnect the HV battery from the car systems, eliminating the vampire drain. Only the very slow self-discharge rate for the Lithium-ion HV battery would remain. A few kWh of the HV battery is not accessible/usable for driving or the car's systems, because it's reserved to prevent the severe damage from "bricking". I'm not sure what the self-discharge rate is, but I understand the HV battery would last for still more months. The small 12V battery would discharge and die, but the large and expensive HV battery would be protected. Worst case scenario, Tesla's warranty covers the cost of bricking.